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Author Topic: multi-switch prop 12+2 decoder  (Read 2555 times)

david48

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multi-switch prop 12+2 decoder
« on: June 16, 2016, 07:26:56 PM »

Well here I go again ,with help from Inertia I now have working bow/stern thrusters(cheers Dave). But now on to my next set back ,I can not get any of the switched outlets to work . The decoder has a 12v supply, and the thrusters work with the knobs on the TX. There is a 12v output from the decoder when the RX is switched on ,but when I try the switches on the TX it will not turn of the supply.
 The instructions for the decoder has this information:- the circuit board of the decoder has two wire links A and B
A  closed for Robbe Futaba system
    open for Graupner Nautic-Expert systems
B  normally closed (memory function for latching switch positions) . You can disable the memory by disconnecting the bridge, in which case all the switch positions are momentary in action ,and the memory effect is eliminated.

Because of my limited intelligence understanding the written word ,I do not know what the statement at B means .
Do I cut the wire to get the decoder to switch or not ,or is there a fault on the decoder because there power at all the outlets.
thanks for the help
David
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g6swj

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Re: multi-switch prop 12+2 decoder
« Reply #1 on: June 16, 2016, 08:36:14 PM »

David,

With regard to text "B" -
A latching switch is a switch that maintains its state after being activated. A push-to-make, push-to-break switch would therefore be a latching switch - each time you actuate it, whichever state the switch is left in will persist until the switch is actuated again.

So switch "B" either makes it a latching switch or not - if you remove link "B" the switch will be momentary only which I don't think you want.

You should check that the mode of the little switch in the 8370 unit matches that on your TX either PCM or PPM

Regards
Jonathan
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g6swj

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Re: multi-switch prop 12+2 decoder
« Reply #2 on: June 16, 2016, 09:22:55 PM »

David,

Have a look at post #4 (link below) - it might make it clear what the wires on the switched output channels are and how they work

http://www.modelboatmayhem.co.uk/forum/index.php/topic,5057.msg50812.html#msg50812
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david48

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Re: multi-switch prop 12+2 decoder
« Reply #3 on: June 18, 2016, 11:08:44 AM »


Decoder problems
Please can someone with this decoder tell me why there is 12v at all the switched outlets when the Module switches on the F14 navy are not operated , am I right in thinking no power until the relevant switch is operated . The two knobs work ok for the thrusters . Ch 7 is used to connect to the decoder. If the decoder has gone faulty what's on the market to replace it .
Thanks  , David
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g6swj

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Re: multi-switch prop 12+2 decoder
« Reply #4 on: June 18, 2016, 11:30:24 AM »

David,

The module switches the negatives lines. The centre (+) pin is always live whilst power applied. You can switch 2 circuits per output, the negative pins are switched in/out of the circuit.

This posting explains it http://www.modelboatmayhem.co.uk/forum/index.php/topic,5057.msg50812.html#msg50812

Example - Lets take one output - it can switch 2 circuits. The centre pin is positive power, is common to both circuits  and always on whilst power is connected from separate external battery.

The outer 2 pins are negative and are switched. So in theory if all working if I connect:

A -  light to left pin and centre pin(+ common power for both circuits) and called this A
B -  light to right pin and centre pin (+ common power for both circuits) and called this B

The switch in one position activates (-) connection on one circuit and A illuminates. If switch moved to other position the other negative(-) pin is then activated and circuit B light illuminates - ( the first negative pin at this point is deactivated)

The image below top part shows the example - 2 light circuits A and B - common (+) line

Regards
Jonathan
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steamboatmodel

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Re: multi-switch prop 12+2 decoder
« Reply #5 on: June 21, 2016, 11:37:39 PM »

It is quite common for microprocessors to switch the ground on or off as the chip can handle more current to ground than it could sourcing it.
Regards,
Gerald.
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nmbrook

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Re: multi-switch prop 12+2 decoder
« Reply #6 on: June 27, 2016, 09:04:05 AM »

I have an F14 with all the bells and whistles but have yet to complete a model that requires the decoders.I was under the impression that 6v was the max supply for the decoder any function that draws more than milliamps or a higher voltage has to run through a seperate switch or speed controller,operated by the decoder.
Having no experience other than reading the manual and what I have been told may mean I stand to be corrected here :embarrassed:


Kind Regards


Nigel
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inertia

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Re: multi-switch prop 12+2 decoder
« Reply #7 on: June 27, 2016, 10:08:00 AM »

I have an F14 with all the bells and whistles but have yet to complete a model that requires the decoders.I was under the impression that 6v was the max supply for the decoder any function that draws more than milliamps or a higher voltage has to run through a seperate switch or speed controller,operated by the decoder.
Having no experience other than reading the manual and what I have been told may mean I stand to be corrected here :embarrassed:

The decoder draws its own power from its connection to the receiver. This provides a nominal 4.8-6v supply for the electronics within the decoder and also for the two servos which can be connected to pins K7 and K8. The switched functions K1-K6 are powered by a separate battery of 4.8-24v which is connected to the BATT pins at the top of the decoder. Each output can switch the supply voltage at up to 800ma if all outputs are used, rising to 1.8A if only one is used. No more than a total of 6A may be drawn. This applies to both the Multiswitch and Multiswitch-Prop decoders, the difference being that the Switch-Prop has two proportional outputs for servos while the Switch has only switched outputs.
If you have one of the Multiprop decoders then all of the outputs are for servos, speed controllers, electronic switches i.e. units which you would normally plug directly into a receiver channel.

I hope that's cleared things up.
DM
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david48

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Re: multi-switch prop 12+2 decoder
« Reply #8 on: June 27, 2016, 11:37:54 AM »

Good morning , these decoder things seem to be a head ringing sort of a thing, with help from Inertia and G6SJW I have the decoder working to a point . Lights and Radar work but when I try the thruster the fuse blows on the distribution board . What  I have tried so far is plugging the thruster in to CH5 on the RX and it works ok . The connections to the decoder are CH7 from RX to decoder , K7/8 out to two P93s , a12v feed from the BD into Batt on the decoder .The thrusters work ok of the RX ,because the middle row of pins are live all the time from the battery and the -NEG are switched is there a chance there could be conflict from K7/8 ,there is a 4.8v output from K7/8 to the P93s . At a loss to find this dead short ,I know its difficult without being there to see what is  going on. Suggestions what should be my next move (do not be silly now that has nearly happened but to much invested )
David   
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inertia

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Re: multi-switch prop 12+2 decoder
« Reply #9 on: June 27, 2016, 12:49:50 PM »

David
K1-K6 will have a permanently live positive pin (centre pin of three) and should show 12v if you connect a voltmeter across that and one of the two adjacent pins and you operate that switch on the Tx. You should NOT be seeing a reading of 12v across the + and - of either K7 or K8 at any point.
Have you tried a servo in either of these two decoder outputs?
What Mode do you have P93 set to?
DM
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g6swj

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Re: multi-switch prop 12+2 decoder
« Reply #10 on: June 27, 2016, 04:38:41 PM »

DM
Quote
should show 12v if you connect a voltmeter across that and one of the two adjacent pins and you operate that switch on the Tx.

This is exactly what David48 and I thought but our experience is different... (Basically don't test it with a volt meter)

The voltage will not change regardless of switch position which leads you to think that the switching is not working!

To help me explain, with the decoder positioned so the RX lead is on the left hand side and taking output K1 as the example number the output pins left to right P1,P2&P3.

You will be able to measure the same voltage P1-P2 and P2-P3 at the same time which is not affected by the TX switches - however the available current you can draw will be virtually zero between one pair either P1-P2 or P2-P3 whilst the other pair will supply specified current draw - flick the relevant switch and the current draw will be limited to all but zero on one pair and the other pair will be able to supply specified current.

Very confusing - I have tested this with kit on workbench - If I am using it incorrectly or there is another explanation I would love to know.
Regards
Jonathan

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inertia

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Re: multi-switch prop 12+2 decoder
« Reply #11 on: June 27, 2016, 05:28:27 PM »

I think the problem is with the ESCs - the six switched circuits appear to be OK. I'm in contact with DW and hope to have it sorted one way or another very soon.
DM
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nmbrook

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Re: multi-switch prop 12+2 decoder
« Reply #12 on: June 27, 2016, 05:29:57 PM »

Thank you DM,yes I have two 2+6 prop/switch modules fitted and decoders.What I was thinking is that I need a polarity reversing module to control each motor connected to each of the 3 way switches on the transmitter?


If this is the case,are these still available given the temporary demise of Robbe?


Kind Regards


Nigel
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